Ductor roller mounting arrangement for a printing machine



F. BOHAC 3,517,614

DUCTOR ROLLER MOUNTING ARRANGEMENT FOR A PRINTING MACHINE June 30, 1970 Filed D60. 1, 1967 r INVENTOR.

United States Patent 3,517,614 DUCTOR ROLLER MOUNTING ARRANGEMENT FOR A PRINTING MACHINE Frantisek Bohac, Krtiny, Czechoslovakia, assignor to Adamovske strojirny, narodni podnik, Adamov, Czechoslovakia Filed Dec. 1, 1967, Ser. No. 687,321 Int. Cl. C41f 31/30 US. Cl. 101-349 4 Claims ABSTRACT OF THE DISCLOSURE The two coaxial bearing sleeves which support the trunnions of a ductor or drop roller in an offset printing machine are received in respective upwardly openrecesses of two hangers mounted on a common support in axially spaced relationship and slotted in planes transverse of the roller axis. A flat latch is pivotally mounted in each slot and spring biased toward a position in which a portion of the latch blocks upward movement of a bearing sleeve from the corresponding recess. An arcuate cam face on the latch portion engages the sleeve and is eccentric relative to the pivot axis of the latch in such a manner that upward pressure of the sleeve against the latch tightens the latter.

Background of the invention This invention relates to printing machinery, and particularly to ductors or drop rollers provided with releasable bearings.

A ductor of an offset printing machine must be removed from the machine from time to time for cleaning and other maintenance operations after which it is returned to its operative position. It is therefore desirable that the bearings of the roller be released easily from the supporting elements, yet, it is necessary that the roller be held firmly in the machine during operation, and not be dislodged by vibration and jarring movement to which it is unavoidably exposed, particularly on high-speed machinery.

Known releasable bearing arrangements either require tools and a relatively great amount of labor for insertion and removal of the drop roller, or they do not reliably lock the rollers to the stationary machine parts during printing.

An object of the invention is the provision of a drop roller or ductor arrangement which combines the advantages of the afore-mentioned known devices while avoiding their shortcomings.

Summary of the invention -In one of its aspects, the invention provides two hangers spacedly mounted on a common support and having upwardly open recesses in their dependent portions. Bearing sleeves for the trunnions of a drop roller are coaxially received in the recesses of the two hangers, and their movement upward and outward of the recesses is normally blocked by respective latch members pivotally fastened in slots of the hangers transverse of the bearing axis. Yieldable means bias each latch member toward a locking position in which a blocking portion of the latch member is adjacent the associated recess.

The blocking portion has an arcuate cam face which engages the associated bearing sleeve in the locking position and is eccentric relative to the pivot axis of the latch member.

Other features, additional objects, and many of the attendant advantages of this invention will readily be appreciated as the same becomes better understood by 3,517,614 Patented June 30, 1970 reference to the following detailed description of a preferred embodiment when considered in connection with the appended drawing.

Brief description of the drawing In the drawing:

FIG. 1 shows a feed roller of an offset printing machine mounted in a releasable bearing arrangement of the invention, in front elevation; and

FIG. 2 illustrates the device of FIG. 1 in partly sectional side elevation.

Description of the preferred embodiment The drawing shows as much of the inking mechanism of an offset printing machine as is needed for an understanding of this invention. All other elements illustrated in the drawing are supported on a shaft 1 pivotally mounted in the frame of the machine in a manner not illustrated and entirely conventional. Two flanged bushings 2 are axially spaced on the shaft 1. An annular portion of an arm 3 is attached to the end portion of each bushing 2 remote from the flange 2 thereof by a pin 4 which diametrically passes through the bushing 2 and the shaft 1 and thus fixedly fastens the bushing 2 and the arm 3 to the shaft.

One end of a hanger 5 is pivotally mounted on each bushing 2 between the flange 2' and the associated arm 3. The depending free end of the hanger is hook-shaped and defines an upwardly open, approximately square recess 10. The free end of the arm 3 is enlarged axially of the shaft 1 so that it extends in a common radial plane with the hanger 5. A helical tension spring 6 whose ends are attached to a pin 7 on the hanger 5 and to a pin 7' on the free end of the arm 3 tends to swing the hanger on the shaft 1 counterclockwise, as viewed in FIG. 2, until a radial abutment face 19 on the hanger 5 engages a threadedly adjustable stop 8 on the arm 3, the adjusted position of the stop 8 being secured by a locking nut 9.

An axial portion of a cast-iron bearing sleeve 11 on which two parallel and opposite flats have been ground is received in the recess 10 of each hanger 5 in such a manner that the fiat surfaces of the sleeve conformingly engage the normally vertical walls of the recess, and rotation of the two sleeves 11 about their common axis is prevented. They receive the trunnions 20 of a drop roller or ductor 12.

Upward movement of the bearing sleeves 11 out of the associated recesses 10 is prevented by latches 13. Each latch 13 is a segmentof a flat ring partly extending about the shaft 1 and is received in a guide slot 14 which bisects an associated hanger 5, except for the hooked end, in a plane perpendicular to the axes of the shaft 1 and of the ductor 12. One end of the latch 13 is pivotally mounted between the two parts of the hanger 5 on a pin 15 above the shaft 1 and is-biased clockwise, as viewed in FIG. 2, by a spiral spring 16 partly coiled about a portion of the pin 15 outside the slot 14 whose free ends abut against the latch 13 and the hanger 5.

The free end of the latch 13 has a cam face 17 which is circularly arcuate and eccentric relative to the pin 15. The cam face 17 is held in engagement with the associated bearing sleeve 11 by the spring 16, and the cam face 17 is inclined in such a manner that upward sliding movement of the sleeve 11 in the recess 10 tends further to swing the latch clockwise and thereby to tighten its hold on the sleeve. The latch is self-locking and does not entirely depend on the spring 16 for holding the sleeve 11 in the recess 10.

During normal operation of the printing machine, the shaft 1 oscillates about its axis to move the ductor 12 toward and away from engagement with a non-illustrated 3 rubbing-down roller under the resilient force of the spring 6 in a manner conventional in itself.

When it is desired to remove the ductor 12, slight manual pressure against flat transverse end faces 18 of the latches 13 causes the latches to swing on the pins 15 and to release the bearing sleeves 11. After the ductor and its bearings have been removed, the latches 13 return to the illustrated position under the urging of the springs 16. In again inserting the ductor 12 and its bearings 11, the bearings are moved against the end faces 18 until the same are flush with the hangers 5, whereupon the bearings can be moved downward into the corresponding recesses 10, and the latches 13 return to the locking position.

No tools are needed for installing or removing the bearing sleeves 11 and the ductor 12, yet the latter is safely held on the shaft 1 under all conceivable operating conditions and cannot escape from the hangers 5.

It should be understood, of course, that the foregoing disclosure relates only to a preferred embodiment of the invention, and that it is intended to cover all changes and modifications in the example of the invention herein chosen for the purpose of the discloser which do not constitute departures from the spirit and scope of the invention set forth in the appended claims.

I claim:

1. Apparatus for mounting a ductor roller in a printing machine comprising a support, a pair of hangers mounted parallel to one another on said support and spaced apart a predetermined distance, each of said hangers having a depending portion ending in a hook member defining an upwardly open recess, a bearing sleeve associated with each of said hangers for mounting the ductor roller and slidably supported in each of said recesses, said bearing sleevs having a common substan tially horizontal axis, each of said hangers being formed with a slot extending vertically of the depending portion parallel to each other and in a plane transverse to the common axis of said recesses, a latch member associated with each of said hangers, comprising an arcuate section pivotally mounted at its upper end to the respective hanger and adapted to have its lower end move within the slot thereof to a position above said recess, spring means for normally biasing said latch member into engagement with the bearing sleeve supported within its associated recess, said lower end of the latch member forming an arcuate cam face adapted to prevent sliding of said bearing sleeve and to lock said bearing sleeve within its associated recess against movement.

2. An arrangement as set forth in claim 1, wherein said recess has two parallel upright walls, and each bearing sleeve has two opposite flat surface portions conformingly engaging said walls for guiding vertical movement of the bearing sleeve into and out of said recess, and for preventing rotation of said bearing sleeve about said common axis.

3. The apparatus according to claim 1 wherein the center of curvature of said latch member is eccentric to the'axis of pivot whereby a locking action is automatically effected.

4. The apparatus according to claim 1 wherein each of the hangers are pivotally mounted to said support, and include spring means for normally biasing the same with respect to the support and adjustable stop means for limiting movement thereof.

References Cited UNITED STATES PATENTS 2,474,160 6/ 1949 Peyrebrune 101348 3,007,407 11/ 1961 Newman et al. 101349 FOREIGN PATENTS 1,942 12/ 1912 Great Britain. 188,135 1 1/ 1922 Great Britain. 113,555 1/ 1926 Switzerland.

ROBERT E. PULFREY, Primary Examiner J. R. FISHER, Assistant Examiner US. Cl. X.R. 30824 

